When removing clothes from washer some tend to have blackish grey small spots on them, what is this?

That sounds like either mold or mildew may have been in the washer from water standing in the machine for some time or a foam backed rug or fabric has been washed in it. If it's persistent, I'd suspect mold. For mold, fill the machine, add a couple of cups of bleach and run through a cycle as if there were clothes in the machine.

If neither of the above seem to work. Look for a rubber/plastic washer or grommet that has dry-rotted and is coming apart.